Reversible Plough

ABSTRACT

A reversible plough with a frame for a 3-point hitch attachment comprises a frame with lower first and second and an upper third attachment point for attachment to a 3-point hitch. A vertical pivot axle supports a plough tool carrier for pivotable movement. The upper third attachment point is located on a vertical pivot plate in a first upper pivot point. A second lower pivot point of said plate is connected to a transversel pivot axis on the frame and a third upper pivot point of said plate is connected to a control link. When the upper link of the 3-point hitch moves backwards, then the plate pivots and moves the control link backwards as well. Said control link extends towards the rear end portion of the frame and is connected to a link arrangement pivotally supported by the vertical pivot axle and connected to the plough tool carrier.

FIELD

The disclosure relates to a reversible plough and more particularly to a reversible plough comprising a frame with a 3-point hitch attachment on a front end portion of the frame.

BACKGROUND

Reversible ploughs are well known in the prior art. They comprise a frame which is attachable to an agricultural vehicle, e.g. a tractor, and further a pivotable plough tool carrier with several plough tools like discs, blades or shares arranged on the carrier for engaging the ground. The plough tools are pivotally mounted to the carrier and can be adjusted to a desirable position in which they engage with the ground. The carrier is supported on the frame for pivotal movement on a vertically extending pivot axle and is placed in its operating positions in a horizontally diagonal oriented position, so that the tools are engaging the ground one behind another and transversely displaced to each other. When pivoting the carrier from its one operating position into its other operating position the plough tools are changing their ground engaging orientation into a reverse position. Several arrangements for automation have been made including the arrangement of hydraulic controls for changing the carrier operating position. However, hydraulic components are costly and therefore not affordable to all customers, so mechanically controlled solutions are still required. Nevertheless, there is still need for easy to use solutions, without the need to leave an operator station, comprising mechanical links for providing a control for an operator to change the carrier without any major efforts and without the need for manual, time consuming adjustments to the carrier or the plough tools. Although some solutions are already known in the prior art there is still some need for improvement with respect to facilitating maintenance, number of parts, complexity and easy operation of said mechanical links.

SUMMARY

In order to provide an improved reversible plough with respect to the above mentioned criteria it is proposed to use a reversible plough with a frame for a 3-point hitch attachment on a front end portion of the frame. The frame comprises lower first and second attachment points for attachment to a first and second lower link of a 3-point hitch and an upper third attachment point for attachment to a third upper link of said hitch. A vertical pivot axle is located on a rear end of the frame and supports a plough tool carrier for pivotable movement around said axle. The upper third attachment point is located on a vertical pivot plate in a first upper pivot point on which the pivot plate and therefore the frame of the plough can be connected to the upper link of a 3-point hitch of a tractor. A second lower pivot point of said vertical plate is connected to a transversel pivot axis on the frame and a third upper pivot point of said vertical plate is connected to a first end of a control link. Therefore, when the upper link of the 3-point hitch moves backwards, and with it the third attachment point, then the vertical plate pivots and moves the control link backwards as well. Said control link extends towards the rear end portion of the frame and is connected to a link arrangement. The link arrangement is pivotally supported by the vertical pivot axle and further connected to the plough tool carrier.

In one embodiment of the invention the link arrangement may comprise a bushing which is arranged on the vertical axle for pivotable movement. The bushing is rigidly connected to a control plate and a control arm, both extending from said bushing towards the front end of the frame, therefore extending between the vertical axis and the control link. The control arm is connected to the plough tool carrier and moves the carrier when being pivoted by the pivot movement of the bushing and the control plate, respectively. The control plate comprises a guide slot to which the control link is slidably connected. For controlling the control plate it is proposed to arrange the guide slot in a generally transverse direction and symmetrically oriented to both sides of a longitudinal axis of the plough tool carrier. Further, the guide slot is placed a distance from the vertical axle and has a first and a second slot end arranged in distance from the vertical axle, so that the first and second slot ends are building a triangular arrangement with the center point of the pivot axle. This enables the control link to provide the bushing with a certain torque around the vertical axle when applying a force on the control plate on one of the slot ends. Due to the rigid connection between the control plate, the bushing and the control arm, said control arm will transfer the torque on the bushing into a control force for pivoting the carrier.

The slot ends may each comprise a notch for a snap-in engagement of the control link with the control plate when sliding within the guide slot from one slot end to the opposite slot end. So, when lifting the plough for pivoting the plough tool carrier a drag force is created moving the control link into the one of the slot end notches and pulling on the control plate in order to create the pivot movement of the carrier. When placing the plough back to the ground the drag force on the control link will be turned into a compression force, so that the control link will be pushed out of the notch and slidably moved along the guide slot into its next end position within the opposite slot end.

In a further embodiment the frame comprises an arcuate frame portion on which one end of the plough tool carrier is slidably supported so that the one end of the plough tool carrier moves slidably along the arcuate frame portion when pivoting from one operation position into a reverse operation position. Further, a latch mechanism is provided in order to control the start of a pivot movement when lifting the plough.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a top view of a reversible plough according to one embodiment in a first operating position,

FIG. 2 shows a cross-sectional side view of the reversible plough along a cross-section plane A-A in FIG. 1,

FIG. 3 shows a side perspective view of a link arrangement for pivoting a plough tool carrier of the reversible plough in FIG. 1,

FIG. 4 shows a first side view of the reversible plough in FIG. 1,

FIG. 5 shows a second side view of the reversible plough in FIG. 1 and

FIG. 6 shows a bottom view of the reversible plough in FIG. 1.

DETAILED DESCRIPTION

With respect to FIGS. 1, 2 and 4 to 6, a reversible plough 10 comprises a frame 12 having a 3-point hitch attachment 14 on a front end portion 13 of the frame 12 for attachment to an agricultural tractor with a 3-point hitch (not shown). The frame 12 comprises a lower first attachment point 16 and a lower second attachment point 18 for attachment to a first and second lower link of the 3-point hitch (not shown) and an upper third attachment point 20 for attachment to a third upper link of said hitch (not shown).

A vertical pivot axle 22 is located on a rear end of the frame 12 and supports a plough tool carrier 24 for pivotable movement around said axle 22.

As best shown in FIG. 2, the upper third attachment point 20 is located on a vertical pivot plate 26 in a first upper pivot point 28 on which the pivot plate 26 and therefore the frame 12 of the plough 10 can be connected to the upper link of a 3-point hitch of a tractor (not shown). A second lower pivot point 30 of said vertical plate 26 is connected to a transverse pivot axis 32 on the frame 12 and a third upper pivot point 34 of said vertical plate 26 is connected to a first end 36 of a control link 38. Therefore, when the upper link of the 3-point hitch (not shown) moves backwards, and with it the third attachment point 20, then the vertical plate 26 pivots around its lower pivot point 30 moving the control link 38 backwards as well.

Said control link 38 extends towards the rear end portion of the frame 12 and is connected to a link arrangement 40, as shown in detail in FIG. 3. The link arrangement 40 is pivotally supported by the vertical pivot axle 22 with a bushing 42 for pivotable movement. The bushing 42 is rigidly connected to a control plate 44 and a control arm 46, both extending from said bushing 42 towards the front end of the frame 12, therefore extending between the vertical axle 22 and the control link 38. As best shown in FIG. 2, the control arm 46 is connected to the plough tool carrier 24 and moves the carrier 24 around the vertical pivot axle 22 when being pivoted by the pivoting movement of the bushing 42 and the control plate 44, respectively.

The control plate 44 comprises a guide slot 48 to which the control link 38 is slidably connected by a bolt 50 slidably placed in the guide slot 48 and supported by a fork-shaped end 52 of the control link 38.

As best shown in FIG. 1, for controlling the control plate 44 the guide slot 48 is arranged in a generally transversal extension to a longitudinal axis 54 (shown in FIG. 1) of the plough tool carrier 24 and symmetrically extending to both sides of said longitudinal axis 54. Further, the guide slot 48 is placed a distance D1 to a rotational axis 56 of the vertical pivot axle 22 and has a first and a second slot end 58, 60, each arranged a distance D2 to the rotational axis 56 of the vertical pivot axle 22, so that the first and second slot ends 58, 60 are building a triangular arrangement with a center point 62 of the vertical pivot axle 22 or the rotational axis 56, respectively. This enables the control link 38 to provide the bushing 42 with a certain torque around the vertical axis 56 when applying a force on the control plate 44 on one of the slot ends 58, 60. Due to the rigid connection between the control plate 44, the bushing 42 and the control arm 46, the control arm 46 transfers a torque on the bushing 42 into a control force for pivoting the plough tool carrier 24.

Each of the slot ends 58, 60 comprises a notch 64, 66 for a snap-in engagement of the control link 38 with the slot ends 58 or 60, respectively. In other words, when the bolt 50 of the control link 38 is sliding along the guide slot 48 and moving from one slot end 58, 60 to the opposite slot end 60, 58, respectively, the bolt so snaps into the notch 64 or 66 on arrival. Therefore, when lifting the plough 10 for pivoting the plough tool carrier 24 a drag force is created moving the control link 38 into the one of the slot end notches 64, 66 and pulling on the control plate 44 in order to create the pivot movement of the plough tool carrier 24. When placing the plough 10 back to the ground the drag force on the control link 38 will be turned into a compression force, so that the bolt 50 on the control link 38 will move out of the notch 64 or 66 respectively, and slide along the guide slot 48 into a position within the opposite slot end 60 or 58, respectively.

The plough tool carrier 24 comprises several pivot supports 68 along the longitudinal axis 54 supporting plough tools 70 in form of discs. On the end of the plough tool carrier 24 a further support 72 is located for supporting a gauge wheel 74. The pivot supports 68 are connected to each other with pivot arms 76 attached to a control link 78 for keeping the orientation of the support pivots 68 aligned to each other. The control arm 46 is attached to the pivot support 68 in front of the vertical pivot axle 22, so that the control arm 46 can act on the pivot support 68 with a control force for pivoting the plough tool carrier 24 around the vertical pivot axle 22.

The frame 12 further comprises an arcuate frame portion 80 on which a front end 82 of the plough tool carrier 24 is slidably supported so that the front end 82 of the plough tool carrier 24 moves slidably along the arcuate frame portion 80 when moving from one operating position into a reverse operating position.

As best shown in FIG. 6, a latch mechanism 84 is provided in order to control or trigger the start of a pivot movement of the plough tool carrier 24 when lifting the plough 10. The latch mechanism 84 comprises a control lever 86 located on a front frame support 88 and pivotally attached to a blocking linkage 90 on the bottom side of the front frame support 88. The blocking linkage 90 extends to both ends of the arcuate frame portion 80 and engages the sliding front end 82 of the plough tool carrier 24 when reaching its operating positions on the respective arcuate frame portion end. The blocking linkage 90 comprises two angular links 92, 94, each pivotally connected with a center pivot 96, 98 on opposite sides on the front frame support 88 and being pivotally connected to each other on one end 100, 102, wherein the other ends 104, 106 form the blocking ends engaging the front end 82 of the plough tool carrier 24. The pivoting control lever 86 is rigidly connected to the center pivot 96 of the angular link 92 pivoting the same. When pivoting the control lever 86 the angular link 92 will be pivoted moving the blocking end 104 towards the front end of the frame 12 into a lifted position from its blocking engagement, thereby causing a movement of the connected ends 100, 102 of the angular links 92, 94 links towards the rear of the frame 12 and thereby moving the blocking end 106 of the other angular link 94 towards the front of the frame 12 into a lifted position. Therefore, by pivoting the control lever 86 to an unblocking direction, indicated by arrow 108, the plough tool carrier 24 will be released. Pivoting the control lever 86 back will latch the plough tool carrier 24 on its sliding front end 82.

Reversing the plough 10 can be initiated by lifting the frame 12 on its 3 point attachment 14. When lifting from the ground the lower links of the 3-point hitch on the tractor (not shown) move up. The upper link of the 3-point hitch moves automatically away from the front end of the frame 12 towards the tractor. The bolt 50 of the control link 38 is thereby placed in one of the slot end notches 64, 66. The control link 38 will be pulled and a force will be created due to gravity of the plough 10. This force creates a torque around the vertical pivot axle 22 as described above. When releasing the latch mechanism 84, the torque will cause the plough tool carrier 24 to pivot around the vertical pivot axle 22. When the plough tool carrier 24 reaches its reverse position the latch mechanism 84 will be activated towards the blocking position and the plough 10 will then be lowered. The upper link of the 3-point hitch will automatically move back turning the former drag force into a compressing force and moving the control link 38 towards the control plate 44, where the control link 38 starts to slide along the guide slot 48 from the one slot end 58, 60 to the opposite slot end 60 or 58, respectively. When the plough 10 starts to be lifted again for reaching the next reverse position, the same movements will take place in just opposite direction starting with the bolt 50 of the control link 38 in slot end notch 66 or 64, respectively.

When pivoting the plough 10 from one operating position into the reverse operating position the gauge wheel 74 will be turned automatically from its one operating side to the reverse operating side. Therefore a control link 110 is placed between the frame 12 and a first pivot arm 112 of a pivot plate 114. A second pivot arm 116 extends from said pivot plate 114 and engages a guide slot arm 118 which is pivotally supported on the rear end of the plough tool carrier 24 and slidably guided by the pivot arm 116. The support 72 of gauge wheel 74 is connected to said pivot arm 116 on the guide slot arm 118. According to the movement of the plough tool carrier 24 the control link 110 will pull on the first pivot arm 112 when the pivot plate 114 starts moving with the rear end of the plough tool carrier 24 and pivots the second arm 116. The second arm 116 will slide towards the pivot of the guide slot arm 118, thereby pivoting it around the end of the plough tool carrier 24 and turning it towards the reverse operating position.

Having described the reversible plough 10, it will become apparent that various modifications can be made without departing from the scope of the accompanying claims. 

What is claimed is:
 1. Reversible plough comprising: a frame with a 3-point hitch attachment on a front end portion of the frame comprising lower first and second attachment points for attachment to a first and second lower link of a 3-point hitch and an upper third attachment point for attachment to a third upper link of said hitch; a vertical pivot axle located on a rear end portion of the frame; a plough tool carrier pivotally mounted on said vertical pivot axle; wherein the upper third attachment point is located on a vertical pivot plate in a first upper pivot point, a second lower pivot point of said vertical plate is connected to a transverse pivot axis on the frame and a third upper pivot point of said vertical plate is connected to a first end of a control link, said control link extending towards the rear end portion of the frame and being connected to a link arrangement which is pivotally supported by said vertical pivot axle and connected to said plough tool carrier.
 2. Reversible plough according to claim 1, wherein the link arrangement comprises a bushing which is arranged on the vertical axle for pivotable movement and is rigidly connected to a control plate and a control arm, both extending from said bushing towards the front end of the frame, wherein the control arm is connected to the plough tool carrier and wherein the control plate comprises a guide slot to which the control link is slidably connected.
 3. Reversible plough according to claim 2, wherein the guide slot extends generally transversely and symmetrically to both sides of a longitudinal axis of the plough tool carrier and a distance from the vertical axle, having first and second slot ends arranged a distance from the vertical axle, so that the first and second slot ends are building a triangular arrangement with the center point of the pivot axle.
 4. Reversible plough according to claim 3, wherein the slot ends each comprises a notch, wherein the control link will be placed into the notch of the first slot end when lifting the plough for pivoting the plough tool carrier and wherein the control link will be released from the notch of the first slot end when placing the plough to the ground after pivoting the plough tool carrier and will be slidably moved along the guide slot for engagement with the notch on the second slot end.
 5. Reversible plough according to claim 1, wherein the frame comprises an arcuate frame portion on which one end of the plough tool carrier is slidably supported so that the one end of the plough tool carrier moves slidably along the arcuate frame portion when pivoting from one operating position into a reverse operating position.
 6. Reversible plough according to claim 1, further comprising a latch mechanism for latching the plough tool carrier and for triggering a pivoting movement of the plough tool carrier from one operating position into a reverse operating position when lifting the frame. 